xiv INTEODUCTION. 



prominent, but not so far down the face as in the Forest variety. 

 In Steppe and Forest horses the neck and chest are short ; in the 

 Plateau variety (owing to the greater length of the cervical 

 vertebras and of the vertebrae carrying the first nine pairs of ribs) 

 the neck and chest are long. In the Steppe and Plateau variety 

 there are five lumbar verteb.ae and a well set-on tail ; in the Forest 

 variety six lumbar vertebrae, rounded hind quarters, and a low 

 set-on tail — in the Celtic pony there is a large taillock, the tail 

 hence differs greatly from the mule-like tail of Prjevalsky's horse. 

 In the limbs one notices differences in the hoofs as well as in the 

 number of callosities and in the form of the metacarpal bone, i.e., 

 of the long bone below the knee which attracts so much attention 

 from breeders. In the Forest horse the hoof is broad and wide 

 at the heels ; in Prjevalsky's horse the hoof is long, narrow and 

 contracted at the heels ; in the Plateau horse the hoof — always 

 small — varies with the habitat, being sometimes wide, sometimes 

 narrow. The metacarpal (shank) bone in the Forest horse is so 

 broad from side to side that the length may be only 5.4 

 times the width at the centre of the shaft — hence in the Forest 

 horse the " bone " is round. In the Steppe and Plateau varieties 

 the metacarpals are long and narrow, with the result that the 

 length may be 7.5 times the width — hence in these types the 

 '' bone " is flat. The Forest and Steppe horses have eight cal- 

 losities (four ergots and four chestnuts); in the Plateau horses, as 

 already n entioned, the only callosities are the two front chestnuts. 

 The three varieties also differ in their colours; the Steppe and 

 Plateau forms are of a yel ow or reddish dun tint with more or 

 less dark points, but beyo"d a narrow dorsal band, there are only 

 the merest vestiges of stripes. The Forest variety is of a dark 

 yellow dun colour with dark foints, a ve y broad dorsal band, and 

 in typical cases, stripes on the face, neck and trunk and above 

 and below the knees and hocks;. 



The importance of realizing the existence of a. Forest and a 

 Plateau variety as well as of a Stefpe (or Prjevalsky) variety 

 becomes evident when we proceed to study the modern domestic 

 breeds. I need only give one or two examples of this. If, as I 

 have indicated, domestic horses have sprung from several wild 

 varieties adapted for different habitats — one like the extinct horse 

 \H.y2mhippus) adapted for a forest life, one like the Miocene horse 

 {Neohi2)pari(f7i) for a life on bo mdless plains, and one like 

 Prjevalsky's ho'-fft for a steppe life — they should differ in their 

 skulls, teeth and lin bs. and by n-easuring the skull and limb 

 bones it sho'dd be possible to estimate from which wild varieties 

 they have inherited their chief characteristics. 



